Wii Music would have been better if it was a launch title during the release of the Wii back in 2006.
Gameplay- Really stright foward for any gamer but it's mostly repetative for some instruments like you would need the nun-chuck for playing the drums, or the piano or if your Mii charcter is dressed as a dog. Some brass instruments like the trumpet or flute is mostly pressing the 1 and 2 buttons on the Wii Controller.
There are other minigames on Wii music where one of them is simular to Guitar Hero you are mostly ringing 2 coloured bells more of childs version of Guitar Hero for younger children. Anothor mini game is a Pitch Recognition test which can be tricky you are mostly listening and reconising music notes if they sound bad or good more of a guessing game.
Best part of Wii Music is the orctrestra where you'll be playing classical music and you also play Nintendo Theme music like The Legend of Zelda or Super Mario Theme which are good for Nintendo fans at least.
Graphics and Sound- If you have played Wii Sports or Wii Fit you can use your Mii charcter to play instrments or if you made more Mii charcters on the Wii they can also appear almost anywhere if your doing an orctrestra or in a band. The Charcters for Wii Music look the same as the Mii charcters but there heads are like Pac-Man/ South Park charcters type if you think about.
Most music you'll be probably be doing alot if your a Nintendo is the Zelda theme, Mario theme or F-Zero theme and try getting a good score on orctrestra. But you can play other classical music with what ever insturment you want. There is also Jamming mode where you can use what ever insturment you like and just play
Overall- If you have a Wii Fit you can use it for playing the drums and also make your own music video which you can use to send to your friends if you have Wi-Fi for your Wii.
To be honest Wii Music would been alot more fun if it was released during the launch of the Wii back in 2006 along with Wii Sport. But also Wii Music is abit disapoiting because I thought that most gamers play any music like Final Fantasy Music or Sonic the Hedgehog theme or even Mario Galaxy music.
But most gamers will find Wii Music disapointing but it's mostly aimed at kids mostly.